A turbine rotor blade having a radially outer shroud is known from EP 2 402 559 A1.
Due particularly to asymmetric overhangs of the shroud relative to the airfoil, centrifugal forces generate stresses in the shroud during operation, which stresses tend to twist the shroud.
Therefore, EP 2 402 559 A1 proposes to provide at least one reinforcing rib in a shroud pocket defined in the circumferential direction by two opposite z-shaped ribs, the at least one reinforcing rib extending substantially in the direction of the maximum or principal axis of inertia of the blade or the radially outer portion thereof.
However, such ribs, which are provided in pockets and inclined relative to the axis of rotation, are difficult to manufacture and may also be unfavorable in terms of fluid dynamics.